CN8223 Datasheet, PDF (59/161 Pages) Conexant Systems, Inc – ATM Transmitter/Receiver with UTOPIA Interface

CN8223
ATM Transmitter/Receiver with UTOPIA Interface
2.0 Functional Description
2.5 Parallel Line Interface
2.5.3 Receive Parallel Interface
Interface connections for the Receive Parallel Interface mode are listed in
Table 2-16. Figure 2-15 illustrates the receive timing for the parallel interface. In
parallel mode, data octets are provided on RXDAT[7:0] with an octet clock (up to
20 MHz) on RXCKI. The octet data is sampled on the falling edge of RXCKI.
The data inputs can be sampled on the rising edge of the input clock by setting
Invert RX Clock Sampling [bit 8] of CONFIG_3 [0x02]. An idle octet indicator
can be provided on RXOD as illustrated in Figure 2-15. The CN8223 ignores all
octets for which the RXOD input is high. This input can be used to mark framing
overhead (non-ATM payload) octets.
Table 2-16. Receive Parallel Interface Mode Connections
Signal Name
Connect to CN8223 Pin
Receive Clock Input (RXCKI)
Receive Octet Disable (RXOD)
Receive Data Input (RXDAT)
RXCKI
RXIN[8]
RXIN[7:0]
Figure 2-15. Receive Parallel Interface Timing
RXCKI
RXDAT[7:0]
Data
Data
(ignored)
Data
Data
RXOD
100046C
Conexant
2-25